Betta fish

Description

The Siamese fighting fish (Betta splendens), commonly known as the betta, is a freshwater fish native to Southeast Asia, namely Cambodia, Laos, Myanmar, Malaysia, Indonesia, Thailand, and Vietnam. While there are 73 species of the genus Betta, only Betta splendens are eponymously called "bettas", due largely to their global popularity as pets: they are among the most widely available aquarium fish in the world, due to their varied and vibrant colour, diverse morphology, and relatively low maintenance. Siamese fighting fish are endemic to the central plain of Thailand and have been domesticated for at least 1,000 years, among the longest of any fish. They were initially bred for aggression and subject to gambling matches akin to cockfighting. Bettas became known outside Thailand through King Rama III (1788-1851), who is said to have given some to Theodore Cantor, a Danish physician, zoologist, and botanist. They first appeared in the West in the late 19th century, and within decades became popular as ornamental fish. Their long history of selective breeding has produced a wide variety of coloration and finnage, earning them the moniker, "designer fish of the aquatic world". Bettas are well known for being highly territorial, with males prone to attacking each other if housed in the same tank; without a means of escape, this will usually result in the death of one or both fish. Female bettas can also become territorial towards one another in confined spaces. Bettas are exceptionally tolerant of low oxygen levels and poor water quality, owing to their special labyrinth organ, a characteristic unique to the suborder Anabantoidei that allows for the intake of surface air. In addition to its worldwide popularity, the Siamese fighting fish is the national aquatic animal of Thailand, which remains the primary breeder and exporter of bettas for the global aquarium market. Despite their abundance as pets, B. splendens is listed as "vulnerable" by the IUCN, due to increasing pollution and habitat destruction. B. splendens usually grows to a length of about 6–8 cm (2.4–3.1 in). Although aquarium specimens are widely known for their brilliant colours and large, flowing fins, the natural coloration of B. splendens is generally green, brown and grey, while the fins are short; wild fish exhibit strong colours only when agitated. In captivity, Siamese fighting fish have been selectively bred to display a vibrant array of colours and tail types.